Neal Henderson MS CSCS

   
    Long discussed, contested, and practiced is the idea of using strength training to enhance or improve endurance performance.  As a physiologist, coach, former elite triathlete, and strength and conditioning specialist, I do have some experience in this area.   In fact, I am asked the question of whether endurance athletes should perform strength training several times each week.  I was involved in research regarding this very topic during my graduate studies - and no, I can’t tell you with 100% scientific back-up that it is either beneficial or harmful to endurance performance.  I can tell you that for every scientific paper that touts a benefit of strength training on endurance performance, there is at least one paper that proves the opposite - that strength training interferes with improvements in endurance, as well as the converse.  Unfortunately, most of the literature on the topic has missed the boat in several areas - at least as it applies to serious endurance athletes.

    First, most of the subjects in the studies that have evaluated concurrent strength and endurance (let’s simpify this to S-E training) have used initially sedentary subjects.  To make the leap of faith that an untrained person will respond in a similar fashion to a highly trained (or even well-trained) endurance athlete is one that I’m not ready to make…are you?  Second, most training studies have used very short durations of concurrent training such that there may not be the actual responses one would expect with either type of training.  It has been shown that during the initial 8 weeks of strength training alone, the primary improvements in measured strength are due to improved neuromuscular firing and coordination - not in any real change in the muscle fibers’ ability to produce force.  So, most studies 8-weeks long or less out shouldn’t even call themselves studies about strength training.

    We also know that endurance training changes can occur in 8-12 weeks, though it typically takes 4-6 months of consecutive training to reach peak endurance performance.  To date, there has not been a study published that has utilized greater than 16-weeks of concurrent training - most ranged from 8-12 weeks.  For me, I’d like to see what happens over 16-24 weeks to really have a firm grasp on what actually can and does happen.  Another major problem with the existing research is that the strength protocols are standard 3 days per week with 3 sets of 10 repetitions performed doing movements that aren’t specific to the sport(s) being trained.  Does anyone really believe that doing bench press is going to improve running performance?  I guess if the running performance measured is the running of the bulls…then being able to push your fellow competitors out of the way and avoid getting gored could be a considered a benefit.  In most other running contexts, I can’t think of any potential benefit of being able to push more weight with the upper body.

    Finally, very few studies of concurrent S-E training have actually measured endurance performance.  As a physiologist and coach, I can say that VO2 max is not a measure of endurance performance…it is simply a measure of maximal aerobic activity.  Last time I checked, I didn’t get a race time or place based off of my last VO2 max test value…I still had to swim, bike, and run and get to the finish line to have an actual endurance performance.  It is possible to improve endurance performance without changing VO2 max…economy of movement is one aspect that few researchers have measured with S-E training.
 
    Since there isn’t much data that relates to triathletes…what should you do?  Well, sometimes you have to read between the lines.  If you go through the list and read each of the papers, you might find a few golden nuggets or pearls of wisdom.  To save you the time and drudgery of reading through several drab scientific texts, here are some key ideas to help you form an educated opinion supported by research.  Here is another article that might be worthy of your time if you’re really interested in the subject.

1. Concurrent strength and endurance training can lower injury rate in runners.

- Strength training does not only affect muscles - it can improve the strength and integrity of tendons.  Having stronger tendons can be effective in reducing over-use injuries such as tendonitis.  If you aren’t injured or don’t get injured as frequently, you are likely to be able to train more (and more effectively), which will likely make you faster over the long-term (if you are training effectively and recovering from your training).

2. Strength training will improve neuromuscular coordination and peak sprint power development.

- This is more important for athletes competing in events that require some kind of sprint effort.  Multisport athletes who qualify in this area would be: XTERRA athletes, elites racing in draft-legal format events, and athletes who dabble in road cycling - especially mass start events.  If you’re an Ironman athlete, you shouldn’t be doing too much sprinting in training or racing…unless you’re doing it all wrong.

3. If you aren’t doing any endurance training, then strength training might maintain some level of endurance performance.

- Don’t try this at home.  Seriously, you are a multisport athlete who competes in endurance competitions.  If you spend long periods of time not doing any endurance training…well, you won’t have much endurance.  Sure, doing some strength training might keep you from losing all of your fitness gains…but you’d be better off not doing strength training and using that time to do some endurance training.

4. Know your limits.  If you are already taxed by the amount of endurance training that you are performing, you likely will not see any benefit from added training of any kind. 

- Often times, endurance athletes need to initially decrease their training volume when adding strength training as the metabolic and mechanical demands on the muscles are considerable.  It is extremely important to be doing the right kind of lifts or movements.  Using poor mechanics or the wrong kind of strength training can lead you down the wrong road.  Remember, train like an athlete - not like the beefcake or fitness model at the gym.  Perform strength exercises that mimic the movements that you make while swimming, cycling, and running - specificity is important!

    So, remember - it’s all about making the choice based on your personal goals, abilities, and capacities.  If you are thinking of adding strength training to your training routine, it’s usually best to start during your transition and base training phases.  Be sure that if you do not have a background with strength training that you consult a strength and conditioning specialist who can help you devise an appropriate routine and teach you proper (and safe) mechanics for your movements.  During periods of high endurance-specific training demand, be cautious with strength training.  It’s usually better to go into maintenance mode for strength workouts once you get into the competitive season. 

    Author Neal Henderson, MS CSCS is a USA Triathlon Elite certified coach and National Strength and Conditioning Association Certified Strength and Conditioning Specialist.  He is the Sport Science Manager at Boulder Center for Sports Medicine and used to squat 500 pounds and power-clean 225 pounds as a high school athlete before turning to triathlon racing in college.
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